24. Anwendung

Gtk.Application encompasses many repetitive tasks that a modern application needs such as handling multiple instances, D-Bus activation, opening files, command line parsing, startup/shutdown, menu management, window management, and more.

24.1. Befehl

Gio.Action is a way to expose any single task your application or widget does by a name. These actions can be disabled/enabled at runtime and they can either be activated or have a state changed (if they contain state).

The reason to use actions is to separate out the logic from the UI. For example this allows using a menubar on OSX and a gear menu on GNOME both simply referencing the name of an action. The main implementation of this you will be using is Gio.SimpleAction which will be demonstrated later.

Many classes such as Gio.MenuItem and Gtk.ModelButton support properties to set an action name.

These actions can be grouped together into a Gio.ActionGroup and when these groups are added to a widget with Gtk.Widget.insert_action_group() they will gain a prefix. Such as „win“ when added to a Gtk.ApplicationWindow. You will use the full action name when referencing it such as „app.about“ but when you create the action it will just be „about“ until added to the application.

You can also very easily make keybindings for actions by setting the accel property in the Gio.Menu file or by using Gtk.Application.set_accels_for_action().

24.3. Befehlszeile

When creating your application it takes a flag property of Gio.ApplicationFlags. Using this you can let it handle everything itself or have more custom behavior.

You can use HANDLES_COMMAND_LINE to allow custom behavior in Gio.Application.do_command_line(). In combination with Gio.Application.add_main_option() to add custom options.

Using HANDLES_OPEN will do the work of simply taking file arguments for you and let you handle it in Gio.Application.do_open().

If your application is already open these will all be sent to the existing instance unless you use NON_UNIQUE to allow multiple instances.

24.4. Beispiel

_images/application_example.png
  1import sys
  2
  3import gi
  4
  5gi.require_version("Gtk", "3.0")
  6from gi.repository import GLib, Gio, Gtk
  7
  8# This would typically be its own file
  9MENU_XML = """
 10<?xml version="1.0" encoding="UTF-8"?>
 11<interface>
 12  <menu id="app-menu">
 13    <section>
 14      <attribute name="label" translatable="yes">Change label</attribute>
 15      <item>
 16        <attribute name="action">win.change_label</attribute>
 17        <attribute name="target">String 1</attribute>
 18        <attribute name="label" translatable="yes">String 1</attribute>
 19      </item>
 20      <item>
 21        <attribute name="action">win.change_label</attribute>
 22        <attribute name="target">String 2</attribute>
 23        <attribute name="label" translatable="yes">String 2</attribute>
 24      </item>
 25      <item>
 26        <attribute name="action">win.change_label</attribute>
 27        <attribute name="target">String 3</attribute>
 28        <attribute name="label" translatable="yes">String 3</attribute>
 29      </item>
 30    </section>
 31    <section>
 32      <item>
 33        <attribute name="action">win.maximize</attribute>
 34        <attribute name="label" translatable="yes">Maximize</attribute>
 35      </item>
 36    </section>
 37    <section>
 38      <item>
 39        <attribute name="action">app.about</attribute>
 40        <attribute name="label" translatable="yes">_About</attribute>
 41      </item>
 42      <item>
 43        <attribute name="action">app.quit</attribute>
 44        <attribute name="label" translatable="yes">_Quit</attribute>
 45        <attribute name="accel">&lt;Primary&gt;q</attribute>
 46    </item>
 47    </section>
 48  </menu>
 49</interface>
 50"""
 51
 52
 53class AppWindow(Gtk.ApplicationWindow):
 54    def __init__(self, *args, **kwargs):
 55        super().__init__(*args, **kwargs)
 56
 57        # This will be in the windows group and have the "win" prefix
 58        max_action = Gio.SimpleAction.new_stateful(
 59            "maximize", None, GLib.Variant.new_boolean(False)
 60        )
 61        max_action.connect("change-state", self.on_maximize_toggle)
 62        self.add_action(max_action)
 63
 64        # Keep it in sync with the actual state
 65        self.connect(
 66            "notify::is-maximized",
 67            lambda obj, pspec: max_action.set_state(
 68                GLib.Variant.new_boolean(obj.props.is_maximized)
 69            ),
 70        )
 71
 72        lbl_variant = GLib.Variant.new_string("String 1")
 73        lbl_action = Gio.SimpleAction.new_stateful(
 74            "change_label", lbl_variant.get_type(), lbl_variant
 75        )
 76        lbl_action.connect("change-state", self.on_change_label_state)
 77        self.add_action(lbl_action)
 78
 79        self.label = Gtk.Label(label=lbl_variant.get_string(), margin=30)
 80        self.add(self.label)
 81        self.label.show()
 82
 83    def on_change_label_state(self, action, value):
 84        action.set_state(value)
 85        self.label.set_text(value.get_string())
 86
 87    def on_maximize_toggle(self, action, value):
 88        action.set_state(value)
 89        if value.get_boolean():
 90            self.maximize()
 91        else:
 92            self.unmaximize()
 93
 94
 95class Application(Gtk.Application):
 96    def __init__(self, *args, **kwargs):
 97        super().__init__(
 98            *args,
 99            application_id="org.example.myapp",
100            flags=Gio.ApplicationFlags.HANDLES_COMMAND_LINE,
101            **kwargs
102        )
103        self.window = None
104
105        self.add_main_option(
106            "test",
107            ord("t"),
108            GLib.OptionFlags.NONE,
109            GLib.OptionArg.NONE,
110            "Command line test",
111            None,
112        )
113
114    def do_startup(self):
115        Gtk.Application.do_startup(self)
116
117        action = Gio.SimpleAction.new("about", None)
118        action.connect("activate", self.on_about)
119        self.add_action(action)
120
121        action = Gio.SimpleAction.new("quit", None)
122        action.connect("activate", self.on_quit)
123        self.add_action(action)
124
125        builder = Gtk.Builder.new_from_string(MENU_XML, -1)
126        self.set_app_menu(builder.get_object("app-menu"))
127
128    def do_activate(self):
129        # We only allow a single window and raise any existing ones
130        if not self.window:
131            # Windows are associated with the application
132            # when the last one is closed the application shuts down
133            self.window = AppWindow(application=self, title="Main Window")
134
135        self.window.present()
136
137    def do_command_line(self, command_line):
138        options = command_line.get_options_dict()
139        # convert GVariantDict -> GVariant -> dict
140        options = options.end().unpack()
141
142        if "test" in options:
143            # This is printed on the main instance
144            print("Test argument recieved: %s" % options["test"])
145
146        self.activate()
147        return 0
148
149    def on_about(self, action, param):
150        about_dialog = Gtk.AboutDialog(transient_for=self.window, modal=True)
151        about_dialog.present()
152
153    def on_quit(self, action, param):
154        self.quit()
155
156
157if __name__ == "__main__":
158    app = Application()
159    app.run(sys.argv)

24.5. Siehe auch

  • Die Eigenschaft ist lesbar.

  • Die Eigenschaft ist lesbar.

  • Die Eigenschaft ist lesbar.

  • Die Eigenschaft ist lesbar.